1. Field of the Invention
The present invention relates to a hydraulic flow regulator, and, more particularly, to a regulator that controls a fluid flow as the pressure of the fluid fluctuates, for instance in a jack.
2. Description of the Related Art
Hydraulic cylinders are common devices used in industry and for the jacking of loads using a jacking mechanism having an input cylinder and an output cylinder. The output cylinder is used to lift the load to a predetermined height with a considerably small force utilized on the mechanical portion that moves the input cylinder. The working principal of the hydraulic jack system provides for an applied small force that moves the input piston of a small cross-sectional area and pushes the hydraulic fluid or oil into an output cylinder, which then forces an output piston of large cross-sectional area to jack up a load.
When an operator of a hydraulic jack needs to lower the load that has been jacked up, the operator typically operates a release valve to allow the fluid to escape the load cylinder. Generally the release valve is a screw that has very little resolution and the fluid will rapidly escape to the fluid reservoir when the output cylinder is under a full load, then as the load comes into contact with a support, thus lowering the load supported by the jack, the pressure in the load cylinder fluid changes and the fluid flow decreases. This disadvantageously then reduces the rate of lowering of the load.
From another perspective the initial lowering speed is generally too high. For example, with a vehicle in a raised position, as the screw valve is moved the vehicle will often lurch downwardly. This can be potentially hazardous to the operator, a condition which it is desirous to avoid.
What is needed in the art is an easy to operate, and inexpensive to manufacture, flow regulator that can be easily incorporated into a jack.